Wireless telegraphy



H. J. ROUND AND G. M. WRIGHT.

WIRELESS TELEGRAPHY.

APPLICATION FILED FEB. 20, I920- 403 40 Patented Jan. 17, 1922.

UNITED STATES PATENT OFFICE.

HENRY JOSEPH ROUND, 0]? LONDON, AND GEORGE MAURICE WRIGHT, CHESTER-.

FIELD, ENGLAND, ASSIGNORS, BY MESNE ASSIGNMENTS, TO RADIO CORPORA- T1011OF AMERICA, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

WIRELESS TELEGRAIPHY.

Specification of Letters Patent.

Patented Jan. 17, 1922.

To all whom it may concern:

Be it known that we, HENRY JOSEPH Room), a subject of the King of GreatBritain. residing at 9 \Voodberry Crescent, Muswell Hill, London,England, and GEORGE MAURICE WRIGHT, a subject of the King of GreatBritain. residin at- Lyngrove, Cromwell Road, Chesterfiel d, England,have invented new and useful Improvements in Wireless Telegraphy, ofwhich the following is a specification.

In direction finding systems, such as the Bellini-Tosi, practicaldifficulties of operation arise owing to the necessity for very accuratetuning of the aerials. his close tuning is required in order that thecurrents generated in the aerials may bear the correct phaserelationship to each other.

According to the present invention we ob viate this dlfliculty byconstructing a Bellini direction finder so that the mutual inductancebetween the field coils and the exploring coil is as great as possible,and by connecting in the circuit of the exploring coil asingle variablecondenser we are then able to use closed loop aerials which practicallyspeaking have of themselves no definite natural period as we can obtainall the necessary tuning bv varyin the capacity of the aforesaidcondenser. We also find that by this invention any errors owing toslight inaccuracies in laying out of the aerials are rendered of lesseffect.

Our invention is illustrated b the accompanying drawing, in which Figure1 is a perspective view and Figure 2 a diagram.

A B C and A D E are the two loop aerials of a Bellini direction findinsystem. These aerials have field coils G H and J K which are arranged inthe usual way but are aperiodic. The exploring coil L is arranged tomove in the field coils and the whole is constructed so that the mutualinductance between L and J K and G H is as great as possible. If thismutual inductance 1s great enough the whole system of aerials and searccoil can be tuned by means of a, variable condenser M in series with thecoil L. By this means we dispense'with the separate tuning of eachaerial while maintaining accuracy and efficiency.

and the search coil and its associated receiver I circuits we find it ofgreat advanta e to connect the mid-points of G H and J 16 together andto earth as shown. of ensuring that the field coils remain definitely atearth potential. We sometimes find it advantageous to earth this pointthrough a condenser, inductance or resistance or a combination thereof.

What we claim is 2-- I 1. The combination of two closed loop aperiodicaerials with an inductance coupled to them and a variable condensercoimected to the inductance.

- 2. The combination of two closed loop aperiodic aerials, an inductanceconnected to each aerial, an earth connection to the middle point ofeach inductance, a third inductance coupled to said inductances and avariable condenser connected to the last mentioned inductance.

3. The combination of two closed loop aperiodic aerials each having afield coil connected thereto, an exploring coil so situated with regardto the field coils that the mutual inductance between it and them is asgreat as possible and a variable condenser connected to the exploringcoil.

4. The combination of two closed loop aperiodic aerials each having afield coil connected thereto, an exploring coil so situated with regardto the field coils that the mutual inductancee between it and them is asgreat as possible, a variable condenser connected to the exploring coiland an earth connection to a point between the two field coils of eachloop.

5. The combination of two closed loop aperiodic aerials each having inits lowest limb an inductance, an earth connection to the middle pointof each inductance, a third inductance coupled to the inductances in thetwo loops and a variable condenser connected to this last mentionedinductance.

6. The combination of two closed loop aperiodic aerials each of whichhas in its lowest limb field coils, an ex loring coil so situated withregard to the field coils that the mutual inductance between it and themThis has the effect regard to the field coils that the mutualinductance'between it and them is as great as possible, avariablecondenser connected to the ends of the exploring coil and an earth 10connection to a' point between the two field coils of each loop.

In testimony that we claim the foregoing as our invention, we havesigned our names this 16th day of January; 1920.

HENRY JOSEPH ROUND. GEORGE MAURICE WRIGHT.

